Chapter 8.4, Problem 5MP

Suppose that revenues from the sale of ski jackets are given approximately by

$R\left(t\right)=6.2+5.8\cos \frac{\pi t}{6}0\le t\le 24$

where R(t) is revenue (in thousands of dollars) for a month of sales t months after January 1.

(A)    Find the total revenue taken in over the 2 year-period—that is, from t = 0 to t = 24.

(B)    Find the total revenue taken in from t = 4 to t = 8.